Place whole bell pepper under preheated broiler; broil under high heat until charred on all sides, turning frequently with tongs. Carefully remove from oven with tongs; place in a paper bag for 15 minutes to steam skin. Carefully remove pepper from bag; remove seeds and ribs. Strip off skin; slice pepper into strips.

In blender or food processor container, place bell pepper, vinegars, garlic, basil, rosemary and sugar. Cover and process until well blended and nearly smooth.